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Antimony as a Tracer of the Anthropogenic Influence on Soils and Estuarine Sediments
2001
Cal-Prieto, M. J. | Carlosena, A. | Andrade, J. M. | Martínez, M. L. | Muniategui, S. | López-Mahía, P. | Prada, D.
The aim of this work was to evaluate antimony (Sb) as apotentially valuable tracer of the anthropogenic impact on soilsand estuarine sediments. Antimony was determined in fifteenroadsoils from a medium-size city, La Coruña (NW of Spain);and twelve sediments from two estuaries (La Coruña and Ares-Betanzos). Sb determination was accomplished in a rapid andreliable way by directly measuring the solid samples with anautomatic ultrasonic slurry sampling-ETAAS device. Soil contentsranged from 0.29 to 8.81 μg g⁻¹. A relation between Sbconcentration and motor vehicle intensity was observed.Regarding estuarine sediments, Sb amounted from 0.22 to 1.51 μg g⁻¹, for the La Coruña estuary and 0.24 to 0.71 μg g⁻¹, forthe Ares-Betanzos estuary; higher Sb values were found forcoastal locations whereas lower contents corresponded to `inner'samples. In order to confirm these findings, other pollutantswere studied: As, Cd, Co, Cr, Cu, Ni, Pb, Zn, aliphatichydrocarbons (AH) and polycyclic aromatic hydrocarbons (PAH).These values, along with the Sb ones, were subjected tomultivariate studies intended to elucidate whether Sb correlated(and to what extent) to other well-known anthropogenic pollutants. Thus, Sb became associated to Cd, Cu, Pb and Zn in road soils and to As, Cu, Zn, PAH, Pb and unresolved hydrocarbons, in sediments.
Mostrar más [+] Menos [-]Rhodophyta Seaweed Species as Bioindicators for Monitoring Toxic Element Pollutants in the Marine Ecosystem of Ghana
2001
Serfor-Armah, Y. | Nyarko, B. J. B. | Osae, E. K. | Carboo, D. | Anim-Sampong, S. | Seku, F.
Six seaweed species of the Rhodophyta family were sampled for atwo-year period from June 1996 to August 1998 along the Atlanticcoast of Ghana (part of the Atlantic Ocean). The species wereanalysed to determine the levels of eleven chemicalelements namely: Al, As, Br, Cd, Fe, La, Mn, Ni, Hg, V and Zn byInstrumental Neutron Activation Analysis (INAA). Al, Br, Ni, andZn were measured in all the seaweed species studied. The elementAl generally showed the highest concentrations in most of thespecies analysed while Hg levels were the lowest. Precision andaccuracy of the method have been evaluated and the detectionlimits also calculated. The results showed high variability inand between species, among sampling sites and times ofcollection. The high values of metal concentrations in themacroalgae suggest that these marine organisms can be used asbiological indicators for studing marine pollution.
Mostrar más [+] Menos [-]Calculation of Terrestrial Inputs to Particulate Organic Carbon in an Anthropogenically Impacted Estuary in the Southeastern United States
2001
Eddins, Stefka G Nikolova
Using ¹³C/¹²C ratios in particulate organic carbon(POC), this study evaluated the fraction of terrestrially derivedPOC in Winyah Bay, South Carolina, an anthropogenically impactedestuary in the southeastern United States. Results from themixing model, which should be viewed as an upper limit becauseof possible dilution from additional potential end-members,showed that between 50 and 90% of POC in the Winyah Bay estuaryis of terrestrial origin. As this POC may be associated withriver-transported pollutants, the potential for accumulation ofpollutants in Winyah Bay is high because POC may become trappedin the estuary as part of either estuarine bottom sediments,circulation or food webs. Thus strategies for pollutionmonitoring and control in the estuary and its watershed arenecessary for the future management of Winyah Bay naturalresources.
Mostrar más [+] Menos [-]Atmospheric Bronze and Copper Corrosion as an Environmental Indicator. A Study Based on Chemical and Sulphur Isotope Data
2001
Nord, A. G. | Tronner, K. | Boyce, A. J.
Corrosion products have been takenfrom 130 copper or bronze outdoor objects all overEurope. Their chemical composition and crystalsymmetry have been determined by means of scanning electron microscopy (SEM/EDS) and X-ray powderdiffraction. Data on location, sampling, objectcharacteristics, general environment and air pollutionlevel; type, colour and chemical composition of thecorrosion layers have been obtained and evaluated by multivariate statistical analysis. The resultsverify that the highest air pollution levels are usually associated with the occurrence of thick,black or dark grey corrosion layers on copper orbronze objects, preferentially containing soot, ironoxide hydroxides, and antlerite,Cu₃(SO₄)(OH)₄. Pale green corrosionusually contains brochantite,Cu₄(SO₄)(OH)₆, and is rather associatedwith less polluted areas. Atacamite, a copper hydroxide chloride with the chemical formula Cu₂Cl(OH)₃, is preferentially observed in coastal regions.In addition, sulphur isotope analyses have beenperformed on eleven corrosion samples from citycenters. The δ³⁴S values are typically inthe region from +4 to +6‰ relative to the sulphurisotope standard CDT (Canyon Diablo Troilite) with amean value of 4.7±1.2 (1σ), therebyindicating that the sulphur in the corrosion layers,in the form of brochantite or antlerite, mainlyoriginates from a similar source despite geographicvariation, most likely sulphur contained in air pollutants.
Mostrar más [+] Menos [-]Photodegradation of halobenzenes in water ice
2001
Klán, Petr | Del Favero, David | Ansorgová, Alena | Klánová, Jana | Holoubek, Ivan
Results from the photolysis ofo, p-dichlorobenzene, bromobenzene, andp-dibromobenzene in water ice are reported. All phototransformations appeared to be based on dehalogenation, coupling, and rearrangement reactions in ice cavities. No photosolvolysis products, i.e. products from intermolecular reactions between organic and water molecules, were found. Many of the products were very toxic substances of a high environmental risk, such as PCBs. The results support our model, in which secondary, very toxic, pollutants can be formed in ice, snow, and atmospheric ice particles from primary pollutants through the action of solar irradiation. The photoproducts may be released to the environment by ice melting and evaporation.
Mostrar más [+] Menos [-]BETR North America: A regionally segmented multimedia contaminant fate model for North America
2001
Macleod, Matthew | Woodfine, David G. | Mackay, Donald | McKone, Tom | Bennett, Deborah | Maddalena, Randy
We present the Berkeley-Trent North American contaminant fate model (BETR North America), a regionally segmented multimedia contaminant fate model based on the fugacity concept. The model is built on a framework that links contaminant fate models of individual regions, and is generally applicable to large, spatially heterogeneous areas. The North American environment is modeled as 24 ecological regions, within each region contaminant fate is described using a 7 compartment multimedia fugacity model including a vertically segmented atmosphere, freshwater, freshwater sediment, soil, coastal water and vegetation compartments. Inter-regional transport of contaminants in the atmosphere, freshwater and coastal water is described using a database of hydrological and meteorological data compiled with Geographical Information Systems (GIS) techniques. Steady-state and dynamic solutions to the 168 mass balance equations that make up the linked model for North America are discussed, and an illustrative case study of toxaphene transport from the southern United States to the Great Lakes Basin is presented. Regionally segmented models such as BETR North America can provide a critical link between evaluative models of long-range transport potential and contaminant concentrations observed in remote regions. The continent-scale mass balance calculated by the model provides a sound basis for evaluating long-range transport potential of organic pollutants, and formulation of continent-scale management and regulatory strategies for chemicals.
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